Can I find an attorney who will verify identification of the beneficiary of a will for a decedent in London, England?

My wife's great aunt died recently and my wife was included in her will. In order to release the bequest, the solicitors are requiring that she provide an attorney's validation of her identification and that she further validate the identification via a Zoom call to examine the copies sent via email against copies in her possession. We understand the need for securing positive identification, but we're not sure why a notarized document would not suffice.